Raising awareness
Workshop in Kentville held to educate public on hemlock woolly adelgid
Officials want people to be aware of a destructive pest as they head out into the forest with the temperature rising.
A hemlock woolly adelgid (HWA) workshop was held April 15 in The Gorge in Kentville to raise awareness and educate the public. The event was organized by the Nova Scotia Invasive Species Council in collaboration with the Town of Kentville.
“As its spreading (in) the province, people are generally becoming a little bit more aware of it and starting to understand how it could impact their day-to-day lives, their relationship with nature (and) their recreational activities,” said council supervisor Kristen Noel.
In January, the furthest east the adlegid had been spotted was south of Wolfville. There have been no further sightings to the east in the past few months.
“We are continuing to detect it at more and more sites within Lunenburg and Kings counties,” said Ron Neville, a survey biologist with the Canadian Food Inspection Agency (CFIA) who co-chairs the Hemlock Woolly Adelgid Working Group with Matthew Smith, a nature legacy ecologist at Kejimkujik National Park. “Based on the rate of spread, we do it expect it to pop up in Hants and Halifax counties sometime within the next few years.”
ORIGINS
Native to eastern Asia, the pest was recorded in Virginia in the 1950s.
In Nova Scotia, it was first discovered in Yarmouth County in 2017. That same year it was spotted as far east as Bear River and the Liverpool area. It is now in the seven western counties of Nova Scotia.
A different strain has been on the west coast of North America for longer, but it doesn’t cause as much damage as there is a beetle and other insects that prey on HWA.
DESTRUCTIVE
HWA are all female and reproduce asexually. There are two generations born per year and each generation can produce more than 150 eggs.
Neville said when the eggs hatch, the adelgid is about the size of pepper and can’t move far on its own.
“But they’re really light and they can get picked up in the wind,” he said.
They can also be transported by animals, on people’s clothing or firewood.
Neville estimated eggs will be hatching in about two weeks’ time.
The pest feeds at the base of hemlock trees’ needles, Neville said, by sucking the sap and starch.
“When you have adelgids feeding on every needle of a branch it just depletes the resources the tree (needs),” he said.
Once infected, the tree starts to thin out and can die in four to 10 years, robbing the forest of majestic trees that are known as foundational species whose canopies provide cool, shaded habitat for animals and insects.
“It’s basically death by thousands and thousands of adelgid all feeding on the tree at the same time,” Neville said.
SURVEY
The bulk of CFIA’s survey work is done from April 1 to June.
“This time of year is a good time to see HWA signs and symptoms,” Neville said.
With more people getting out to enjoy the nice weather this spring, he encourages people to keep an eye out for signs of the pest.
One of the easiest ways to identify HWA is looking at underside of a hemlock branch. An infected tree will have white egg sacks that looks like cotton balls at the base of the needles.
One of the workshop participants described it like “hemlock head lice.”
Residents can report HWA to their local CFIA office, the council at www.nsinvasive.ca or by uploading observations with photos to www.iNaturalist.org.
Noel said early detection and rapid response is a crucial aspect of invasive species management.
“The longer a species is established and has time to multiply, reproduce and spread, the harder it’s going to be to manage.”
SLOWING THE SPREAD
Noel said everyone can help in slowing the spread of HWA.
“We play a really important role in the spread of invasive species, so we play a really important role in stopping them,” she said. “One of the simplest things you can do to stop the spread of forest pests is not moving firewood. So, when you’re going camping this summer, don’t bring firewood with you. Buy it where you’re going to burn it.”
At the end of the trip, leave any unused firewood there.
“That’s all it takes,” Noel said. “You can introduce a new species to a different ecosystem where it doesn’t belong, and it can wreak havoc.”
People should also use a lint roller on their clothes and boot brushes when leaving the woods to ensure they are not transporting pests to other areas.
More information is available on the Nova Scotia Hemlock Initiative website at https://www.nshemlock.ca.